Spector, 67, faces 15 years to life in prison if convicted of murdering actress Lana Clarkson with a gunshot through her mouth at his Los Angeles area home in February 2003.
Los Angeles Superior Court Judge Larry Fidler issued new instructions to the jury on Thursday aimed at breaking an impasse after two days of legal arguments with lawyers on both sides.
Fidler withdrew a jury instruction -- seen as central to the defense case -- that said the prosecution must prove beyond a reasonable doubt that Spector pointed a gun at Clarkson and the gun ended up inside her mouth while in Spector's hand for them to find him guilty.
Instead he told the jury they could consider a range of possible scenarios.
Jurors had reported confusion over the original instruction and Fidler agreed it "misstates the law."
The defense has argued that the 40-year-old actress, who was working as a nightclub hostess when she met Spector, was depressed over her career and finances and shot herself in the mouth, either deliberately or by accident.
Prosecutors said during the trial that even if the gun went off mistakenly, Spector could be convicted of murder because his actions showed a conscious disregard for human life.
Spector, who did not testify in his defense, is famous for pioneering the "Wall of Sound" recording technique in the 1960s and for his work with The Beatles, The Ronettes, Tina Turner and Cher.